1. Field of the Invention
This invention relates to an antenna apparatus for receiving or transmitting radiowaves.
2. Description of the Prior Art
An antenna apparatus, having a microstrip patch antenna on a first substrate for receiving or transmitting radiowaves and a radiowave circuit on a second substrate for receiving or a radiowave signal from the microstrip patch antenna or supplying a radiowave signal to the microstrip patch antenna, first and second substrates being combined to provide a hybrid structure or a monolithic structure to reduce a loss in the coupling pass between the microstrip patch antenna and the radiowave circuit, is known.
FIG. 12 is a perspective view of a prior art monolithic antenna apparatus. A first chip having a microstrip antenna 202 formed on a bottom surface of a quartz substrate 201 and a ground conductor 203, having a slot 204 or a window, formed on a top surface of the substrate 201. A second chip comprising an MMIC 205 having a GaAs substrate and a down-converter 206, and a microstrip line 207 for coupling to the microstrip patch antenna 202. First and second chips are bonded such that the microstrip patch antenna 202 is coupled to the microstrip line 207 through the slot 204 by electromagnetic coupling. This is disclosed in a paper Published in Volume 2, at c-50 of the autumn meeting 1992 of The Institute of Electronics, Information and Communication Engineers.